Study On Pozzolanic Reaction And Fluidity Of Blended Cement Containing Treated Palm Oil Fuel Ash As Mineral Admixture
Loading...
Date
2011-06
Authors
Chea, Chandara
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The aim of this work is to study on pozzolanic reaction and fluidity of
blended cement containing treated palm oil fuel ash as mineral admixture. Palm oil
fuel ash (POFA) was ground in a ball mill to produce ground palm oil fuel ash
(GPOFA), and further treated at 500 °C for 1 hour to remove the unburned carbon,
namely treated ground palm oil fuel ash (TGPOFA). Raw materials have been
characterized in terms of chemical composition, carbon content, mineral
composition, morphology and physical properties. The fluidity, heat of hydration and
pozzolanic reactivity of blended cement containing GPOFA and TGPOFA as well as
pozzolanic reactivity in GPOFA/TGPOFA lime system were investigated, while the
mechanical properties of blended cement such as standard consistency, setting time
and mortar’s strength were also studied. The results show that the heat treatment has
reduced unburned carbon content from 6.01% to 0.07% with the increase in glassy
phases from 67.22% to 73.89%, without causing the agglomeration of particles,
improving the fluidity and pozzolanic reactivity of TGPOFA in blended cement. The
fluidity of blended cement pastes containing TGPOFA (10%-40%) are approaching
the fluidity of OPC paste without superplasticizer (SP), when SP at dosage of 0.2% is
added to blended cement pastes. TGPOFA has low pozzolanic reactivity at the early
stage of hydration with low total heat of hydration at 7 days. To achieve compressive
strength of mortar higher than 75% of OPC mortar at the age of 28 and 91 days (long
term), as specified by ASTM C 618, TGPOFA can be used as mineral admixture in
blended cement up to the replacement ratio of 20% and 40%, respectively. It can be
concluded that the removal of unburned carbon results in the improvement of fluidity
and pozzolanic reaction of blended cement containing TGPOFA as mineral
admixture.
Description
Keywords
Pozzolanic reaction and fluidity of blended cement , containing treated palm oil fuel ash